My math thinking is very confusing, and I always go crazy. . For example, what is the difference between 1 and 10? There are several numbers from 1 to 10. The difference between the two makes me half dead. This can be imagined as a tree planting problem. There are1-1kloc-0/0 numbers, and each number is a tree, arranged in a row.

Say how much time there is between 1 and 10, that is, how many spaces are there in the middle of the tree. You can draw a picture and see, exactly nine.

There are several numbers from 1 to 10, that is, how many trees to count, which must be 10.

Larger numbers can also be solved in a similar way.